Timing apparatus



March 2, 1948. L. A. MARIHART TIMING AP ARATUS Filed March 2, 1946INVENTOR. Leo A. Mar/barf F'IIE IEI Patented Mar. 2, 1948 UNITED STATESPATENT orrics TIMING APPARATUS Leo A. Marihart, Monterey, Calif.

Application March 2, 1946, Serial No. 651,663

6 Claims.

This invention relates generally to timing apparatus of the type adaptedto provide a series of recurrent responses in accordance with thereception of recurrent impulses.

In many types of equipment it is frequently desirable to provideelectrical or mechanical responses having a time interval between thesame corresponding to the time interval between sequential appliedimpulses, but with a definite time lag between each applied impulse andits corresponding response. Relatively complicated equipment has beenproposed for this purpose, as for example a tape perforator, togetherwith contacting means synchronized with the perforator and operating inaccordance with the perforations in the tape. In general however suchtiming apparatus has been too complicated for many types of equipment,particularly where the service required is relatively severe and doesnot permit the supervision by highly skilled technicians. In additionmany prior types of timing apparatus have lacked accuracy and speed andhave not been susceptible of quick adjustment to suit differentoperating conditions.

It is an object of the present invention to provide a relatively simpletype of timing apparatus which will provide recurrent or sequentialresponses at a desired time interval following the reception of appliedimpulses.

A further object of the invention is to provide apparatus of the abovecharacter which will be capable of relatively high speed operation, andwhich will afford relatively accurate timing.

Additional objects of the invention will appear from the followingdescription in which the pre ferred embodiment has been set forth indetail in conjunction with the accompanying drawing.

Referring to the drawing:

Figure 1 is a plan View showing timing apparatus incorporating thepresent invention.

Figure 2 is a side elevational view partly in section, showing thetiming apparatus of Figure 1.

Figure 3 is a side elevational view illustrating another embodiment ofthe invention.

Figure 4 is a detail illustrating another embodiment of the invention.

The apparatus illustrated in the drawing consists of a suitable mountingsupport or frame 1 which is provided with suitable journals for therotatable shaft II. This shaft is connected to other equipment to drivethe same at either a continuous or predetermined rate as will bepresently explained. Mounted upon shaft it there is a wheel I2, theouter periphery 13 of which forms what can be termed a ircular trackway.The

2 sides of the wheel are shown provided with suitable flanges M todefine the sides of the trackway.

A plurality of relatively small transfer elements iii are frictionallyand slidably retained upon the trackway 13. In the embodiment of Figures1 and 2 these elements are in the form of small permanentelectromagnets, formed of suitable metal having relatively high magneticpermeability. The shaping of these elements can be horseshoe fashioned,with the end faces iii of the two branches H being shaped concave tocontact flush upon the periphery [3. The wheel itself, or at least thatpart forming the periphery i3, is made of suitable magneti material suchas iron or steel. The magnetic attraction between the elements l5 andthe periphery 13 forms a convenient and simple slidable frictionalengagement, whereby the elements can be held stationary while the wheelrevolves. When an element is released, it moves in synchronism with thewheel until again arrested.

Releasable means is utilized for retaining the elements l5 and forreleasing them singly upon the receipt of impulses. Thus in thisinstance a retention or star wheel I8 is provided, which is carried bythe rotatable shaft l9. Wheel i3 is provided with projectingcircumferentially spaced fingers 2| adapted to engage the forward facesof the elements is as illustrated in Figure 2. Mounted to rotatetogether with wheel 53 there is a ratchet wheel 22 adapted to be engagedby the pawl 23. This pawl in turn is connected to operating means suchas the solenoid 24. When an electrical impulse is received by thesolenoid 2G, pawl 23 is lifted to release the ratchet wheel 22, and as aresult the ratchet wheel together with wheel 18 rotate a given angularamount to per: mit the release of one element i 5, but to then engageand retain the next succeedin element. A released element travels insynchronism with the wheel until it is returned to the row of elementsbeing retained by the wheel I8.

Means is provided. in conjunction with the wheel l2 to eiiect a responsewhen a released element passes through a given position. Thus an arm 26is provided which serves to support a suitable electrical switch unit2?. The operating member 28 of this switch extends into the path ofmovement of the elements 15. Thus when an element engages member acircuit is closed or opened to eifect the desired response. It isdesirable that the positioning of the switch 27 be adjustable, wherebythe time interval between the receipt of an impulse and the effecting ofa corresponding response, may be adjusted to suit requirements. Thus inthis instance arm 26 is shown movable about the shaft H, and is retainedin an adjusted position by nut 29 which extends through a segmental slot3|, and which is threaded into the support It).

Operation of the apparatus described above can be reviewed as follows:The wheel'li. is continuously rotated and the retained elements l areheld magnetically in frictional engagement with the periphery [3. Thesource of impulses, presumed in this instance to be electrical, isapplied to the solenoid 24. Upon receipt of an impulse pawl 23 istemporarily lifted to permit limited movement of the wheel I8, wherebythe first element of the row of elements is released. A released elementI5 is accelerated practicallyinstantaneously to thereafter move insynchronism with the wheel l2. In Figure 2 one such released element isshown travelling over the top of the wheel. Within a predetermined timeinterval following its release theelement contacts member- 28 of theswitch 2'! thus either openingor closing an electrical circuit. In thismanner a desired response is obtained which'can be used in various waysdepending upon the equipment with which the apparatus is employed.

In certain instancesthe shaft H and wheel I2 can be operated at aconstant rate in order to I provide at all times a fixed time intervalbetween the receipt of an impulse, and the eifecting of acorrespondingresponse. However, in other instances the operation ofwheel l2 may be at a variable rate in synchronism however with anoperating memberof the equipment with which the apparatus is being used.As one specific example of equipment with which my apparatus can beused, reference can bemade to the automatic agricultural machinedisclosed in my copending application Serial Number 482,6'79, filedApril 12, 1943, now Patent No. 2,400,562. When used with such a machinewheel I2 is connected to rotatein synchronism with the rotation of theground wheels of the vehicle, and the impulses are produced bylight'indications from a photoelectric cell. The recurrent responsesobtained serve to operate a plant cutting mechanism, and the timing madepossible by my'apparatus is such that the cutting mechanism is therebyoperated exactly in accordance with the location of the plantresponsiblefor the initiating impulse.

The embodiment of Figure 3 is similar to Figures 1 and 2,-but in thisinstance an idler wheel 33 is provided in addition to thewheel I2. Anendless steel band 34 engages both wheel l2and idler 33, and can be madeof suitable magnetic material such as spring steel. The elements 15engage the surface of the band 34, and therefore an extended trackway isprovided. A plurality of response switches 36.3! are provided in this instance, and these switches are mounted adjustably' to enable theirmovement to diiferent positions along the trackway. Apparatus of thistype enables'ane'xtended timelap'se between receipt of an impulse; andthe eifecting of a correspondingresponse.

Although the use of magnetic elements is deemed desirable and simplifiesthe construction of the apparatus, it is possible to obtain thefrictional retention by means other than magnetic attraction. Thus asshown in Figure e'the elements 4! are retained in place by the overlyinga'nnular flanges 42, and the two parts did, 411) of this element areurged apart by the use of one or more springs 43. Thus'a suitableslidable frictional engagement is' obtained with the periphery of thewheel, thereby enabling retention in the same manner as the magneticelements of Figures 1 and 2, and release in response to the receipt ofan impulse to effect movement in synchronism with the trackway.

It will be evident that various additional alterations and adaptationscan be made to suit various design requirements and various types ofequipment. In most installations it is desirable to provide suitablelubricating means to minimize wear between the transfer elements and theperiphery of the wheel, as for example by encasing the entire timingapparatus in a suitable housing with the wheel i2 being partly immersedin oil.

' My timing apparatus is relatively simple in construction andoperation, and in addition it aifords a relatively high degree ofaccuracy. Operation can be at a relatively high rate, without danger ofmechanical failure and without involving inaccuracies.

I claim:

1. In timing apparatus adapted to providea series of recurrent responsesin accordance with the reception of recurrent impulses, meansproviding acontinuously moving track-way, a plurality of transfer elements slidablyand frictionally engaging the trackway, trigger means associated withthe trackway for retaining a plurality of said transfer elementsstationary in a row one behind the other, said trigger means beingadapted to be operated by received impulses to release the first elementof a retained element, and means located at a station along the-trackwayadaptd to be actuated by a transfer element moving along the trackwayafter release'of the same.

2. In timing apparatus adapted to provide a series of recurrentresponses in accordancewith the reception of recurrent impulses, meansproviding a continuously moving endless trackway, a plurality oftransfer elements slidably and frictionally engaging the trackway,trigger means for retaining a plurality of said transfer elementsstationary relative to the trackway'and in single file one behind theother, said trigger means operating responsive to the reception of animpulse to release the first element of the row whereby said element isfree to move along the trackway, and means located at a station alongsaid trackway and-adapted to'be actuated by a transfer element duringmovement of the latter.

3. In timing apparatus adapted to provide a series of recurrentresponses'in accordance with the reception of recurrent impulses, meansproviding a continuously moving trackway, said trackway includingelectrically magnetic material adjacent the surface of thesame,'a'plurality of electro magnetic transfer elements slidably andfrictionally magnetically retained upon the trackway, trigger means forretaining a plurality of said transfer elements in single fileone'behind the other and relatively stationary with respect to thetrackway, said trigger means being adapted to release the first elementin the row upon receiving an impulse, and means located at a stationalong said trackway adapted to be actuated by a moving transfer element.

4. In timing apparatus adapted to provide a series of recurrentresponses in accordance with the reception of recurrent impulses, acontinuously rotating Wheel having its outer periphery formed to providea circular trackway, a plurality of transfer elements slidably andfrictionally engaging said trackway, trigger means for retaining aplurality of said transfer elements relatively stationary and in singlefile one behind the other, said trigger means being adapted to releasethe first one of said row of elements responsive to the reception of animpulse, whereby the released element is thereby caused to move togetherwith the trackway, means located along the trackway adapted to beactuated by a moving transfer element to eifect a desired response, andmounting means for said last named means enabling adjustment of the sameto different locations along the trackway.

5. In timing apparatus adapted to provide a series of recurrentresponses in accordance with the reception of recurrent impulses, meansproviding a continuously moving endless trackway, a plurality oftransfer elements slidably and frictionally engaging the trackway, eachelement being provided with spring means serving to effect a frictionalengagement with the trackway, trigger means for retaining a plurality oftransfer elements stationary relative to the trackwayand in single fileone behind the other, said trigger means operating responsive to thereception of an impulse to release the first element of the row wherebysaid element is free to move along the trackway, and means located at astation along said trackway and adapted to be actuated by a transferelement during movement of the latter.

6. In timing apparatus adapted to provide a series of recurrentresponses in accordance with the reception of recurrent impulses, acontinuously rotating wheel having its outer periphery formed to providea circular trackway, a plurality of transfer elements slidably andfrictionally engaging said trackway, trigger means for retainin aplurality of said transfer elements relatively stationary and in singlefile one behind the other, said trigger means being adapted to releasethe first one of said row of elements responsive to the reception of animpulse, whereby the released element is thereby caused to move togetherwith the trackway, and means located along the track- 'way adapted to beactuated by a moving transfer element to effect a desired response.

LEO A. MARIHART.

Certificate of Correction Patent No. 2,437,168.

March 2, 1948. LEO A. MARIHART It is hereby certified that the addressof the inventor in the above numbered patent Was erroneously describedand specified as Monterey, California, Whereas said address should havebeen described and specified as County of Monterey, California; and thatthe said Letters Patent should be read with this correction therein thatthe same may conform to the record of the c ase in the Patent Oflice.Signed and sealed this 18th day of May, A. D. 1948.

THOMAS F. MURPHY,

Assistant C'ommissz'oner of Patents.

Certificate of Correction Patent No. 2,437,168. March 2, 1948.

LEO A. MARIHART It is hereby certified that the address of the inventorin the above numbered patent was erroneously described and specified asMonterey, California, Whereas said address should have been describedand specified as County of Monterey, Caliform'a; and that the saidLetters Patent should be read With this correction therein that the samemay conform to the record of the case in the Patent Ofiice.

Signed and sealed this 18th day of May, A. D. 1948.

THOMAS F. MURPHY,

Assistant C'ommissz'oner of Patents.

